1. Field of the Invention
The instant invention discloses a novel device to store and ship sterile micropipets without the breakage presently incurred. The disclosed closure cap maintains the micropipet suspended within the shipping tube and prevents breakage due to the swinging of the micropipet during movement.
2. Brief Description of the Prior Art
Micropipets, or capillary tubes, are frequently used to gather, measure and/or transport various types of liquid specimens, such as blood and sperm, as well as chemical solutions and suspensions. Micropipets are small, thin glass tubes designed for drawing liquid by means of capillary action, or applied suction, and retaining such liquid through surface tension, adhesion or applied suction. Micropipets handle small quantities of liquids, up to 1 ml, while the standard pipets will range in capacity from 1.0 to 50.0 ml. The delicate construction of the pipets requires extreme caution in handling and shipping. For many biological specimens the pipets are required to be sterile and it is preferable that the pipets be shipped in a sterile atmosphere ready for use rather than requiring sterilization just prior to use.
Commercially available stoppers for test tubes are made from a flexible, inert material. The body portion of the stopper is provided with a receiving passage dimensioned to received the outer diameter of the pipet being sealed. U.S. Pat. No. 4,576,595 to Aas discloses an improvement over the prior art for anaerobically sealing a capillary tube containing a liquid sample. The '595 patent solves a problem of air expulsion by venting to the atmosphere the inner space of the stopper while the open tube end is inserted into a skirt portion.
Cook et al discloses a stopper for use in containers for blood collection in U.S. Pat. No. 4,893,636 and 5,060,659. The stopper is particularly designed for use with relatively small size blood collection tubes and enables these tubes to be used with tube holders sized for use with larger collection tubes. The stopper is provided with a diaphragm portion which allows insertion of a collection tube from the collection device to the smaller tube.
U.S. Pat. No. 5,203,825, issued to Haynes et al, discloses a Capillary Tube Assembly Including A Vented Cap which allows a liquid to be drawn into the capillary tube. U.S. Pat. No. 5,188,607 and U.S. Pat. No. 4,786,281 both deal with valve connectors for use with syringes, etc.
Although the foregoing prior art discloses caps for tubes used in the collection and transference of specimens, none address the problem of sterility. Additionally, none of the caps disclosed above are designed for safe shipment of the pipets.
A method for shipping blood sampling glass vials is disclosed in U.S. Pat. No. 4,777,964 and U.S. Pat. No. 4,979,515 to Briggs et al. The '964 patent discloses a home use AIDs sample gathering kit, wherein the user gathers the blood sample in the provided glass vials, seals the vials with a putty substance and mails the vials to a testing facility using the provided cardboard base member 12. The Briggs patents do not address the issue of sterility as neither the vials nor the shipping container would be able to remain sterile after home use. The vials used in the Briggs patent must be manufactured of heavier weight glass, thereby forming a thicker wall, than pipets due to the minimum amount of protection provided by the lightly padded cardboard base.
U.S. Pat. No. 5,131,404 discloses a transportation device which is constructed to handle capillary tubes. The capillary tube carrier tube 1 has a closure cap 3 and an internal divider 5 which subdivides the interior of the tube 1 into cells for receiving the capillary tubes 7 after the samples have been drawn. A pad 8 is positioned in the bottom of the tube 1 for cushioning the bottoms of the capillary tubes 7. The cap 3 has a layer of closure putty 18 adhered to the inside of the top end thereof for use in plugging an end of capillary tubes placed therein after specimen samples have been drawn into the capillary tubes. A shoulder 19 is formed on the interior side wall of the cap 3 for engaging the top surface of the carrier tube 1 to limit the extent of telescoping of the cap 2 over the tube 1. This ensures that a gap will be preserved between the top ends of the capillary tubes 7 in the tube 1 and the putty layer 18 in the cap 3. The device of the '404 patent places four capillary tubes within the same carrier tube and places them vertically within a carrier. This method, although providing sufficient protection for carrying, would not provide sufficient protection for shipping. Additionally, to maintain sterility, shipment from the manufacturer should only be a single pipet per shipping container. Once a shipping container is opened, the sterility is lost and the remaining pipets would be contaminated.
The prior art is replete with caps for use with test tubes and capillary tubes. None of the prior art, however, has addressed the problem of safely shipping sterile pipets. Safe shipment of delicate pipets cannot easily and reliably be accomplished by combining a prior test tube cap and a vial. The instant invention overcomes the problems of the prior art by disclosing a closure cap which retains the pipet safely within a shipping tube, allowing for safe, sterile transportation.